Sudden onset of soreness at the base of the left thigh should first rule out the presence of a traumatic injury. Fractures caused by trauma or strains of the hip muscles may cause hip pain in the short term. If trauma is ruled out, the first thing to consider is the disorder of the hip joint itself, such as hip subluxation or even total dislocation due to hip dysplasia, and secondary acetabular labral injury, which may cause sudden pain at the base of the thigh. Hip impingement syndrome is common in younger patients, often combined with glenoid labral injury or even intra-articular free bodies, and may lead to sudden pain in the thigh. Lower lumbar disc herniation also often causes discomfort in the hip, but this discomfort rarely manifests as sudden soreness, and most have a slow onset.